Holding apparatus

ABSTRACT

A device holding apparatus comprising a base plate; a hollow pad guard provided on the base plate; a pad pin inserted to the pad guard movably in an axis direction and having a through hole; a pad provided at a tip of the pad pin and having a through hole connected to the through hole of the pad pin; and a bellows pad provided on the base plate, having a through hole connected to the through hole of the pad pin and being elastic in the axis direction; for holding by suction a device by the pad by applying a negative pressure to the through hole of the bellows pad, the through hole of the pad pin and the through hole of the pad.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a device holding apparatuspreferably used for an electric device testing apparatus for testing avariety of electric devices, such as semiconductor integrated circuitelement (hereinafter, referred to representatively as ICs).

[0003] 2. Description of the Related Art

[0004] A testing apparatus for testing a finally produced device, suchas an IC chip, is necessary in a producing process of a semiconductordevice, etc. As one kind of such testing apparatuses, an electric devicetesting apparatus for testing an IC chip under applying a thermal stressof a normal temperature, a higher temperature and a lower temperaturethan a normal temperature is known. It is because IC chips are requiredto guarantee as a feature thereof to operate well under a normal, highand low temperature.

[0005] In this kind of an electric device testing apparatus, a test isconducted after a large number of pre-test IC chips loaded on a customertray are reloaded on a test tray conveyed in the testing apparatus, andtested IC chips are reloaded to customer trays of different categoriesin accordance with the test result. A device holding apparatus calledpick-and-place is used for such a reloading operation of IC chips.

[0006] There is known a device holding apparatus of the related artusing a vacuum suction force wherein a rubber pad is used for absorbingimpacts device errors and in a portion contacting an IC chip.

[0007] However, in a testing apparatus of a type conducting thereloading operation of IC chips in a low temperature chamber, an errorin picking up an IC chip was liable to occur due to the rubber padbecoming hard in the low temperature environment. Also, there has been adisadvantage that static electricity charged in an IC chip cannot beremoved when the IC chip contact portion was comprised of an insulatorlike rubber, etc.

[0008] Accordingly, adoption of a highly conductive metal pad wasconsidered, however, an impact by a metal pad becomes large at the timeof contacting an IC chip and the IC chip is liable to be damaged, so aspeed of approaching to the IC chip had to be slower to prevent this,and it has been a bottleneck of the reloading operation at a higherspeed.

SUMMARY OF THE INVENTION

[0009] An object of the present invention is to provide a device holdingapparatus excelling in an effect of removing static electricity and aneffect of preventing damages on devices.

[0010] (1) According to a first aspect of the present invention, thereis provided a device holding apparatus, comprising a base plate; ahollow pad guard provided on the base plate; a pad pin inserted to thepad guard movably in an axis direction and having a through hole; a padprovided at a tip of the pad pin and having a through hole connected tothe through hole of the pad pin; and a bellows pad provided on the baseplate, having a through hole connected to the through hole of the padpin and being elastic in the axis direction; for holding by suction adevice by the pad by applying a negative pressure to the through hole ofthe bellows pad, the through hole of the pad pin and the through hole ofthe pad.

[0011] In this device holding apparatus, a pad is approached to a deviceto contact, and in this state, a negative pressure is applied to athrough hole of a bellows pad, a through hole of a pad pin and a throughhole of a pad. As a result, the device is sucked by the pad, and at thesame time, the bellows pad is shrank due to the negative pressureapplied to the through hole and the device is sucked and picked uptogether with the pad and the pad pin.

[0012] In the present invention, a force acting on the device at thetime of bringing the pad close to the device to contact is only ownweights of the pad and the pad pin and an elastic force of the bellowspad. Accordingly, even when the pad approaches at a high speed, theforce acting on the device is small and possibility of damaging thedevice becomes small. Furthermore, since the force acting on the deviceis small, the pad can be comprised of conductive metal materials and aneffect of removing static electricity is large.

[0013] Note that when releasing the device, the negative pressure havingbeen applied to the through hole of the bellows pad, through hole of thepad pin and through hole of the pad until then is stopped, or a positivepressure is brought to act to the contrary. As a result, the bellows padhaving been shrank until then is stretched and the pad and the pad pinare lowered and the device is released.

[0014] (2) According to a second aspect of the present invention, thereis provided a device holding apparatus comprising a base plate; a hollowpad guard provided on the base plate; a pad pin inserted to the padguard movably in an axis direction and having a through hole; a padprovided at a tip of the pad pin and having a through hole connected tothe through hole of the pad pin; and an elastic body provided betweenthe base plate and the pad pin for giving to the pad pin a force in itstip direction; and a sealing body for forming an airtight chamber on abase end side of the pad pin; for holding by suction a device by the padby applying a negative pressure to the airtight chamber, the throughhole of the pad pin and the through hole of the pad.

[0015] In this device holding apparatus, a pad is brought close to adevice to contact, and in this state, a negative pressure is applied toan airtight chamber, a through hole of a pad pin and a through hole of apad As a result, the device is sucked by the pad, and at the same time,an elastic body is shrank due to the negative pressure applied to thethrough hole and the device is sucked and picked up together with thepad and the pad pin.

[0016] In the present invention, since the pad and the pad pin areprovided on a base plate via the elastic body, it is possible to surelyhold a device by suction without using a rubber pad and it becomesparticularly suitable to a use in a low temperature environment.

[0017] Also, a force acting on the device at the time of bringing thepad close to the device to contact is only own weights of the pad andthe pad pin and a reacting force of the elastic body. Accordingly, bysuitably adjusting an elasticity coefficient of the elastic body, theforce to be acted on the device is small even if the pad approaches at ahigh speed, and the possibility of damaging the device becomes less.Furthermore, since the force acting on the device is small as such, thepad can be comprised of conductive metal materials and an effect ofremoving static electricity is large.

[0018] Note that when releasing the devices, the negative pressurehaving been applied to the airtight chamber, through hole of the pad pinand through hole of the pad until then is stopped, or a positivepressure is brought to act to the contrary. As a result, the elasticbody having been shrank until then is stretched and the pad and the padpin were lowered and the device is released.

[0019] (3) It is not particularly limited in the above invention, but itis preferable that a tip of the pad is more protruding than that of thepad guard when the negative pressure is not applied.

[0020] Also, it is not particularly limited in the above invention, butit is preferable that the pad, pad pin and base plate are comprised of aconductive material.

[0021] Alternately, instead of this, it is more preferable that the padguard is comprised of a conductive material and the device contacts thetip of the pad guard when the negative pressure is applied.

[0022] It is not particularly limited in the above invention, but thepad pin preferably comprises a rotation stop mechanism. An angle of aheld device is aligned by the pad pin because of the provision of therotation stop mechanism to it.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] These and other objects and features of the present inventionwill be explained in more detail below with reference to the attacheddrawings, wherein:

[0024]FIG. 1 is a disassembled perspective view of a device holdingapparatus according to an embodiment of the present invention;

[0025]FIG. 2 is a perspective view from below of the device holdingapparatus shown in FIG. 1;

[0026]FIG. 3 is a sectional view for explaining an operation of thedevice holding apparatus shown in FIG. 1;

[0027]FIG. 4 is a sectional view for explaining an operation of thedevice holding apparatus shown in FIG. 1;

[0028]FIG. 5 is a sectional view of another embodiment of a deviceholding apparatus of the present invention; and

[0029]FIG. 6 is a sectional view for explaining an operation of thedevice holding apparatus shown in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] First Embodiment

[0031]FIG. 1 is a disassembled perspective view of a device holdingapparatus according to an embodiment of the present invention, FIG. 2 isa perspective view from below of the device holding apparatus shown inFIG. 1, and FIGS. 3 and 4 are sectional views for explaining anoperation of the device holding apparatus shown in FIG. 1.

[0032] A device holding apparatus 1 of the present embodiment comprisesa base plate 11, a hollow pad guard 12 provided on the base plate 11, apad pin 13 having a through hole 131 inserted to the pad guard 12movable in the axis direction, a pad 14 having a through hole 141connected to the through hole 131 of the pad pin 13 and a bellows pad 15provided on the base plate 11, having a through hole 151 connected tothe through hole 131 of the pad pin 13, and stretchable in the axisdirection.

[0033] The base plate 11 is mounted on an XYZ-axis drive mechanismoutside the drawing and the entire base plate 11 is movable about anX-axis, Y-axis and Z-axis of an electric device testing apparatus, etc.The base plate 11 is provided with an alignment pin 111 for aligning toa tray, etc. loaded with an IC chip 2 to be held and a push pin 112.

[0034] The pad guard 12 is fixed on a lower surface of the base plate 11with a screw, etc. and a pad pin 13 is inserted therein as shown in FIG.3 so that the pad pin 13 is movable up and down only in the Z-axisdirection.

[0035] The pad pin 13 is formed a through hole 131 inside and the abovepad guard 12 is inserted thereto. A not circle flange 132 (a long circlein the present embodiment) is formed at an upper end of the pad pin 13,and by fitting the long circle flange 132 in a also long circle throughhole 113 formed on the base plate 11, the pad pin 13 is unable to rotateabout the Z-axis direction. Note that the pad pin 13 is movable in theZ-axis direction about the pad guard 12 and base plate 11 as shown inFIG. 3.

[0036] A pad 14 contacting the IC chip 2 is airtightly fit in at the tipof the pad pin 13 and a through hole 141 is formed inside. The pad 14can be suitably changed for use in accordance with a size and shape ofthe IC chip to be held.

[0037] On the other hand, a block 16 for supporting the bellows pad 15is fixed on the upper surface of the base plate 11 and an upper end ofthe bellows pad 15 is fixed by using a pin 161. The block 16 is formed athrough hole 162 connecting to a vacuum generation apparatus (negativepressure generation apparatus) outside the drawing, also the bellows pad15 is formed a through hole 151. The through hole 162 of the block 16,the through hole 151 of the bellows pad 15, the through hole 131 of theabove pad pin 13 and the through hole 141 of the pad 14 are connected inan airtight state.

[0038] The bellows pad 15 is comprised of an elastic material, such asrubber, and its bellows portion is elastic. The lower end of the bellowsportion is provided so as to contact the flange 132 of the pad pin 13.

[0039] Note that on the junction face of the lower surface of the block16 and an upper surface of the base plate 11, a diameter (width) of anconcave portion 163 of the block 16 is set smaller than the diameter ofthe through hole 113 of the base plate 11. As a result, even if the padpin 13 moves up, an upper limit is decided by the flange 132 contactingthe pad pin 13. Namely, the block 16 has a stopper function of the padpin 13.

[0040] Also, in the present embodiment, the pad 14, pad pin 13, padguard 12 and base plate 11 are comprised of a highly conductive metalmaterial and static electricity charged in the IC chip is released tothe ground via the pad 14, pad pin 13, pad guard 12 and base plate 11.

[0041] An operation will be explained next.

[0042] When holding an IC chip, the base plate 11 is first moved toright above the IC chip 2 loaded on the tray 3, etc. and then lowereduntil the pad 14 touches the IC chip 2.

[0043]FIG. 3 shows the state, where a force acting on the IC chip 2 atthis time is only own weights of the pad 14 and the pad pin 13 and areacting force of an elastic force of the bellows pad 15. Accordingly,if the pad 14 collides with the IC chip 2 at the time of lowering thebase plate 11 at a high speed, a force to be acted on the IC chip 2 issmall and likeliness to be damaged is small. Also, since the force to beacted on the IC chip 2 is small as such, the pad 14 can be comprised ofa conductive metal material, etc. as explained above. As a result,static electricity charged on the IC chip 2 can be released to theground via the pad 14, pad pin 13, pad guard 12 and base plate 11, sothat it is possible to prevent the IC chip from being damaged by thestatic electricity.

[0044] As shown in FIG. 3, the pad 14 is brought to contact the IC chip2, the vacuum drawing is performed in this state, and a negativepressure is applied to the through hole 162 of the block 16, the throughhole 151 of the bellows pad 15, the through hole 131 of the pad pin 13and the through hole 141 of the pad 14. As a result, the IC chip adheresby suction to the pad 14. At the same time, the negative pressureapplied to the through holes 141, 131, 151 and 162 shrinks a bellowsportion of the bellows pad 15 as shown in FIG. 4, and the IC chip 2together with the pad 14 and the pad pin 13 is picked up by suction.Note that the bellows pad 15 continues to shrink until the flange 132 ofthe pad pin 13 touches the lower surface of the block 16.

[0045] As shown in FIG. 4, after the IC chip 2 is held, the base plate11 is elevated to be moved to a desired position.

[0046] It is sufficient to conduct an inversed operation to release theheld IC chip 2. Namely, the base plate 11 is moved to right above adesired tray 3 and lowered until the pad 14 holding the IC chip 2 comesto a slightly upper position of the desired position of the tray 3. Thevacuum drawing is stopped in this state and the negative pressure havingbeen applied to the through hole 162 of the block 16, the through hole151 of the bellows pad 15, the through hole 131 of the pad pin 13 andthe through hole 141 of the pad 14 is released. At this time, a positivepressure may be applied for improved releasing of the IC chip 2.Consequently, the bellows pad 15 having been shrank until then stretchesdue to its own elasticity, the pad 14 and the pad pin 13 are presseddownward as shown in FIG. 3, and the IC chip 2 touches the tray 3 and isreleased there.

[0047] Second Embodiment

[0048]FIG. 5 is a sectional view of another embodiment of a deviceholding apparatus of the present invention and FIG. 6 is a sectionalview for explaining an operation of the device holding apparatus.

[0049] The device holding apparatus 1 of the present embodiment uses aspring 17 instead of the bellows pad 15 comparing with the above firstembodiment.

[0050] Namely, there comprises a base plate 11, a hollow pad guard 12provided on the base plate 11, a pad pin 13 having a through hole 131inserted to the pad guard 12 movably in the axis direction, a pad 14having a through hole 141 connected to the through hole 131 of the padpin 13 attached to a tip of the pad pin 13, a pad holder 18 provided tosurround the pad pin 13 and the pad 14, a spring 17 (an elastic body ofthe present invention) for giving a force to the pad pin 13 in thedirection to its tip, and a packing 20 (a sealing body of the presentinvention) for forming an airtight chamber 19 on the base end side ofthe pad pin 13.

[0051] Here, the spring 17 is provided between the spring holder 21provided at the base end of the pad pin 13 and the block 22. Also, thepacking 20 is held at its outer diameter by being sandwiched between theblock 22 and the block 23 and held at its inner diameter beingsandwiched between the pad pin 13 and the spring holder 21 via aretainer 24. The airtight chamber 19 is to be formed between the throughhole 131 of the pad pin 13 and the through hole 251 of the block 25 dueto the existence of the packing 20.

[0052] In the present embodiment, the pad 14, pad pin 13, pad guard 12and base plate 11 are comprised of a highly conductive metal materialand static electricity charged on an IC chip is released to the groundvia the pad 14, pad pin 13, pad guard 12 and base plate 11.

[0053] An operation will be explained next.

[0054] When holding an IC chip, the base plate 11 is first moved toright above the IC chip 2 loaded on the tray 3, etc. and then lowereduntil the pad 14 touches the IC chip 2.

[0055]FIG. 5 shows the above state. In the device holding apparatus 1 ofthe present embodiment, since the spring 17 gives to the pad 14movability in the Z-axis direction without using a rubber material, etc.which becomes hard in a low temperature environment, etc., there is nopossibility of a positioning error caused by shrink of such a rubbermaterial and the IC chip 2 can be precisely held.

[0056] Also, a force acting on the IC chip 2 in the state shown in FIG.5 is only own weights of the pad 14 and the pad pin 13 and an elasticforce of the spring 17. Accordingly, when an elasticity coefficient ofthe spring 17 is adjusted in accordance with need, even if the pad 14collides with the IC chip 2 at the time of lowering the base plate 11 ata high speed, a force acting on the IC chip 2 is small and thepossibility of damaging the IC chip 2 is small. Also, since the forceacting on the IC chip 2 is small as such, the pad 14 can be comprised ofa conductive metal material as explained above. As a result, staticelectricity charged on the IC chip 2 can be released to the ground viathe pad 14, pad pin 13, pad guard 12 and base plate 11, so that it ispossible to prevent the IC chip from being damaged by staticelectricity.

[0057] As shown in FIG. 5, the pad 14 is brought to contact the IC chip2, the vacuum drawing is performed in this state, and a negativepressure is applied to the through hole 251 of the block 25, theairtight chamber 19, the through hole 131 of the pad pin 13 and thethrough hole 141 of the pad 14. As a result, the IC chip 2 adheres bysuction to the pad 14. At the same time, the negative pressure appliedto the through holes 141, 131, airtight chamber 19 and through hole 251shrinks the spring 17 as shown in FIG. 6, and the IC chip 2 togetherwith the pad 14 and the pad pin 13 is picked up by suction. Note thatthe spring 17 continues to shrink until the upper end of the springholder 21 touches an inner surface of the block 22.

[0058] As shown in FIG. 6, after the IC chip 2 is held, the base plate11 is elevated to be moved to a desired position.

[0059] It is sufficient to conduct an inversed operation to release theheld IC chip 2. Namely, the base plate 11 is moved to right above adesired tray 3 and lowered until the pad 14 holding the IC chip 2 comesto a slightly upper position of the desired position of the tray 3. Thevacuum drawing is stopped in this state and the negative pressure havingbeen applied to the through hole 251 of the block 25, the airtightchamber 19, the through hole 131 of the pad pin 13 and the through hole141 of the pad 14 is released. At this time, a positive pressure may beapplied for improved releasing of the IC chip 2. Consequently, thespring 17 having been shrank until then stretches due to its ownelasticity, the pad 14 and the pad pin 13 are pressed downwardly asshown in FIG. 5, and the IC chip 2 touches the tray 3 and is releasedthere.

[0060] Note that the embodiments explained above were described tofacilitate the understanding of the present invention and not to limitthe present invention. Accordingly, elements disclosed in the aboveembodiments include all design modifications and equivalents belongingto the technical field of the present invention.

1. A device holding apparatus, comprising: a base plate; a hollow padguard provided on said base plate; a pad pin inserted to said pad guardmovably in an axis direction and having a through hole; a pad providedat a top of said pad pin and having a through hole connected to thethrough hole of the pad pin; and an elastic body provided between saidbase plate and said pad pin for giving to said pad pin a force in itstip direction; and a sealing body for forming an airtight chamber on abase end side of said pad pin; for holding by suction a device by saidpad by applying a negative pressure to said airtight chamber, thethrough hole of said pad pin and the through hole of said pad.
 2. Thedevice holding apparatus as set forth in claim 1, wherein a tip of saidpad is more protruding than a tip of said pad guard when said negativepressure is not applied.
 3. The device holding apparatus as set forth inclaim 1, wherein said pad, said pad pin and said base plate arecomprised of a conductive material.
 4. The device holding apparatus asset forth in claim 1, wherein said pad guard is comprised of aconductive material and said device contacts the tip of said pad guardwhen said negative pressure is applied.
 5. The device holding apparatusas set forth in claim 1, wherein said pad pin comprises a rotation stopmechanism.